Heat and Cool a House

Naturally, without a Furnace or Air Conditioner

This concept was invented and tested in 1977

Imagine storing about 30 MILLION Btus of summer heat to use for heating
a house in winter! Since a medium-sized house near Chicago needs
only around 40 million Btus for an entire winter's heating, this would
massively reduce heating bills, consumption of oil or gas, pollution
and global warming! A slightly larger version could even provide 100%+ of
the house's heating needs!

Imagine the SAME house storing around 12 MILLION Btus of late winter cooling
to easily provide the 4 MBtu of air conditioning cooling generally used
in an entire summer!

Now imagine that this is not very expensive to install (with the house
value probably being enormously higher, too!). Unfortunately,
this concept is really only best compatible with NEW CONSTRUCTION
buildings, and would be far less beneficial in trying to use it
for any existing buildings. Amazingly, most ways
of installing this system are TOTALLY INVISIBLE after it is installed,
and it is compatible with virtually ANY house style or layout!

This is as GREEN as one can get! Simply "shifting" the effects
of summer and winter seasonal weather, with NO fossil fuels required
at all. Actually, not even any woodstove or methane or any
alternative heating fuel is likely even needed!

And there are very simple and crude (thereby inexpensive) methods
of "boosting" the performance of this system by collecting
a little extra sunlight on any sunny winter days!

Text Font Face

.

Text Size

.

Background

Color

.

(for printing)

This presentation was first placed on the Internet in
March 2002. The concept had been developed and tested on a small
scale in the late 1970s.

This is not even any super-complicated idea! It is essentially storing
all that heat or coolness in a VERY highly insulated "room" hidden
completely underneath the house. It is actually OBVIOUS! (We just
did a lot of Engineering to maximize the performance, so the home
occupants would probably never know that a conventional furnace and
A/C were not providing their comfort.)

During new house construction, it is possible to provide for nearly free air
conditioning and greatly reducing heating costs. This is true for the vast
majority of homes, and could be usable for some businesses, and the cost is
quite reasonable. This concept is not actually any "collection"
system itself, but rather an immense and effective storage system for heat
(in winter) or cooling (in summer). The heating concept still needs to come
from any of a variety of heating sources, whether that is solar, a woodstove,
or conventional heating sources. Actually, one of those seems ideally
compatible with the Sub-Basement storage system, a Solar-Heating - Low-Tech Active System

However, the storage is unique as it is designed to use
"very crude" sources of heat, WITHOUT having to collect 250°F air
or the like. It is actually designed to be able to use air like that that
collects in a closed car on a sunny summer day, between 120°F and 140°F,
and so the technology of the collection can be very simple and even
"crude"!

In the combined heating-cooling concept, a separate source of
cooling MAY be needed (depending on the climate. For many climates,
the massive storage capability can provide enough house air
cooling for an entire summer! OR the huge energy storage capability
can be divided into two (or more) sections, where one could have a
supply of heat while the other had a supply of coolness, such as for
a late Spring day when heat is needed at night and in the morning but
cooling may be needed in the afternoon. And for those warmer climates
where extra cooling might be needed, our related
"Free Air Conditioning" (which is an array of buried, sealed
underground air passageways to capture cool from the cool soil deep
underground, like in caves) is an excellent choice. In a
slightly modified version of this storage, which could then only be used
for cooling, the external cooling system may be unnecessary.

This is SERIOUS storage! Our normal intention is to
design a storage of at least 30,000,000 Btu of heating capability
(a hundred times more than others even dream about!) This system can be
Engineered for a wide variety of climates and occupant expectations,
but our generic planning is usually to plan for a situation where
DURING THE FIRST THREE MONTHS OF WINTER around 10 million of
those Btus would get lost through the excellent insulation, which leaves the
other 20 million Btus to heat the house! Since decently designed modern
houses commonly need around 40 million Btus of actual heating for a whole
winter, this approach takes care of HALF OF EVERY YEAR'S HEATING BILLS!

Actually, in most cases, it will work BETTER than that, and handle
most or even all of the house's heating needs. We use an extremely
conservative approach and generally choose to use
very conservative values in our designing, specifically, of being
able to get the storage up to just 120°F at the beginning of the winter.
(This low storage temperature permits us to store the heat for a LONG time!
The far hotter storage temperatures that most solar systems try to use
cannot store heat for more than a few days at most, as they lose heat
like crazy through the insulation they use.)

Say that our storage is identical but might have a little better insulation
and that it is heated to just a little warmer, around 140°F at the beginning
of the winter. That is then about 60% extra capacity, meaning nearly the
whole winter's heating load could be provided! It is also very easy
to make the heat storage chamber a little taller than the eight feet than we
describe, to then have even greater heat storage, but we again have
tried to stay conservative, and also kept the footprint of the
heat storage chamber entirely under the area of the house, and also
kept the chamber having just an eight-foot height, such that
conventional concrete basement construction procedures could easily
be used.

For most climates, cooling is even easier! The system mentioned
above commonly can have around 13,000,000 Btus of cooling capability
at the start of a summer. A 30,000 Btu/hr central air conditioner
needs to run for about 420 hours straight to provide that much cooling.
In many climates, a standard house actually uses around 3 or 4 million
Btus of cooling during an average summer.

The Concept

Do you plan a basement for this new house? If so, consider making a
full sub-basement underneath it! That's essentially it! If you were
NOT intending to put a basement under the house, consider having one built.
Using poured concrete, a very common method. Maybe an extra thousand
dollars of excavation cost, and an extra thousand dollars of concrete,
and labor (These estimates depend on WHERE you are and WHAT the attitudes
of local Contractors are! It is possible that these numbers might be
several times higher where you are, but even then, it is still a great deal,
since you would eliminate at least $1000 of heating bills and $1000 of cooling
bills EVERY YEAR FOREVER. There are some additional costs, mostly slab
insulation and our favorite " PVC thinwall field pipe", but they
tend to be moderate expenses. There are actually two nearly identical storage
versions, one for heating only or heating and cooling, and the other for
cooling only. For the cooling only, for around (possibly) a few thousand
dollars differential in the construction cost of a new house, you could have
completely normal air conditioning without having to dig up the whole
yard (as in our Free Air Conditioning) and without paying for a
conventional central A/C unit (which
generally costs several thousand dollars that you would save!)
By eliminating the need for the central A/C unit, you might even
be able to cancel out the differential cost of this system!
(These costs are only if the contractors involved are "friendly"
and whom will be kind in their cost additions. Many contractors
dread anything new or unusual, and they might charge ten times that much,
to make sure that they would still make a profit even if unexpected
construction complications occurred!)

This sub-basement structure would not be used as a room. It would actually
be painted with a waterproof sealer, REALLY well insulated on all sides, and
then entirely filled back in with relatively standard backfill earth
materials, and used as a "heat storage" chamber. A complex
arrangement of hollow tubes gets buried in the storage material to provide
the necessary methods to get heat into and out of the storage. Once this
sub-basement was made and filled in
(and then properly compacted), a standard basement floor would be poured
on top of it, and the house built normally above it. In other words,
the final house would show absolutely no evidence of the sub-basement
even existing! The house would be absolutely "normal"! That
allows almost infinite flexibility in the architecture and style of the
house's design and construction.

The final basement floor WOULD have some ducts sticking up through it at
various places, to either send hot air down into the storage or to
remove warm air to go to one or more rooms (it can very easily be
Zoned so that different parts of the house could be kept at different
temperatures). The system is even compatible with hydronic heating/cooling
where water piping is used instead of air ducts.

Among many additional options available, INSIDE the 120°F storage material,
a relatively small chamber could be built, and well insulated, where
that chamber would only lose heat to the 120°F material surrounding it,
and so it could be maintained at an even higher temperature. For example,
if it were kept at a constant 160°F or 180°F, then water pipes running
through that higher temperature material would come out at roughly
that higher temperature. This would be for people who did not feel
that hot water at 120°F was hot enough!

Why?

What would be the point of this? Imagine a modest-sized house, of
40 feet by 25 feet, or 1,000 square feet floor area. This sub-basement
would then have 1,000 square feet of area and 8 feet in height, or
around 8,000 cubic feet of the earth materials trapped inside it.
At a density of around 100 pounds
per cubic foot, that's around 800,000 pounds of heat storage
materials. Using some standard engineering information, this huge amount
of storage is able to store around 500,000 Btu of heat (or cool) for
each degree (F) of temperature change of the material.
When the material is heated to 120°F, that is 50 degrees warmer than
the 70°F comfort temperature of the house, so there would be
50 * 500,000 or 25 million Btus of heat storage. If the storage is
heated to 140°F, that would be around 35 million Btus of available
heat storage. Simple, huh?

If the sub-basement was built with a 10-foot height instead of 8-feet,
those numbers would be proportionately increased to 31 million Btus
and 44 million Btus.

Cooling

First, consider cooling. If this house is in a climate similar to
Chicago's, the natural ground temperature is around 53°F. If, in the
Spring, the storage is permitted to revert to its natural deep earth
temperature, then all of the 800,000 pounds of storage would be at
53°F at the beginning of the Summer. If the desired summer house
temperature is the common 76°F, that means that the storage
starts out the summer season containing
around (76°F - 53°F) * 500,000 or 11.5 million Btus of cooling!

What is the expected house use of cooling? In a climate like Chicago's,
there are commonly around 20 days each summer where a central
air conditioner is used for the six hours of the afternoon. That's
120 actual hours of air conditioning that is needed in a summer.
A modest-sized house such as the above would often have a central air
conditioner rated at 30,000 Btu/hr (2.5 tons). Multiplying these
numbers gives a full summer's air conditioning usage of around
3.6 million Btus of cooling.

Note that for Cooling Only, no insulation would be needed to be installed
inside the walls and floor of the sub-basement chamber. This actually
allows the chamber to naturally cool by losing heat into the deep
soil directly below it, for even greater capacity.

Since the proposed storage could provide the initial 11.5 million Btus
plus constant bonuses due to the floor being cooled by the deep soil under
it, ALL of the 3.6 million Btus of cooling needs would easily be taken
care of! No other air conditioning system would be needed, ever!
The cooling-only version of this storage even constantly and naturally
replenishes itself, so its capabilities are actually even greater.

Regarding the heating-cooling
version, if the climate is such that additional summer cooling is
likely to be required, our related Free Air Conditioning system
can simply ahd easily connect into this storage.
Not only would this eliminate the annual summer electricity
usage for air conditioning (forever!) but it would even eliminate
the initial cost of buying and installing the conventional air
conditioning system. That's several thousand dollars of initial
cost that is eliminated, greatly offsetting the cost of the sub-basement.

In case it is overlooked, a LOT of thermal insulation is involved when
you intend to store heat or cool for MONTHS! R-60 would be an
absolute minimum, with R-100 more likely for many climates and
situations. That is a LOT of foam insulation, and actually represents
a major cost in installing this system.

For some climates, it might even be appropriate to pour an additional
partition wall to separate the sub-basement into two separate chambers.
One would be intended to be used for heating and the other for cooling.
On a late May day, heat might be extracted from the one during the night
and in the early morning, while coolness could then be extracted
in the afternoon! Even better, different rooms of the house could
extract heat or coolness per the calls of standard wall thermostats
turning on blowers!

Bottom line: ALL air conditioning is taken care of, forever, without
the big electricity bills of conventional air conditioning, and without
any Freon refrigerants that might be environmentally bad.

Heating

There are even wonderful heating benefits from this system!

If, in the Autumn, either solar heating or any of a variety of other heat
sources is used to warm up the storage, then maybe by November 1, the
storage could have been gradually gotten up to the desired 120°F.
That stored heat could then be used during the winter for heating the
house. Certainly, all of November, December and January should be completely
provided for. But if February and March heat is also desired, no real
problem, just TALLER sub-basement and storage material and THICKER insulation
to reduce long-term heat losses. Notice that we say WARM and not HOT!

This is meant as a very
"low-tech" system. You have certainly noticed that the interior
of a closed car can soon get over 140°F on a sunny summer day. The point is,
getting this massive storage up to, say 120°F, over several weeks is
quite easy without having to resort to any exotic equipment. Many other
heat sources are possible, too, like a woodstove or similar. Even the
HG 3a device which we invented to allow cut lawn grass and leaves to
naturally decompose, which gives off a LOT of heat, could be used!

When anyone else talks about trying to provide "solar heating"
for domestic hot water or for space heating, they always try to
store the heat at 200°F or above. Yes, that allows a small volume
of storage material to hold a lot of heat, a good thing. However,
it causes enormous heat losses through surrounding insulation
if the heat is to be stored more than three or four hours!
We see great wisdom in minimizing the amount of heat lost through
the insulation. With our design storage temperature of only
120°F, our heat loss rate is less than half that of a 200°F storage!
This is a central reason why our storage can provide heat for a full
house for MONTHS!

Using this very conservative value of 120°F for the top temperature
of the storage, let's do the math. If a desired house temperature is
the usual 70°F, then the storage would have
(120°F - 70°F) * 500,000 or 25 million Btus of heating available for the
house at the beginning of the winter.

In Chicago's fairly nasty climate, our modest-sized house, if reasonably
well insulated, might have an annual heating load of 40 million Btus.
That means that around half of the entire house's winter heating load
could easily be provided by our massive storage, without turning
on any furnace or using any heating fuel, EVEN IF IT IS ONLY MAXXED AT
120°F! (It actually turns out to be almost exactly
half for this example, because several million Btus are lost through the
insulation over those months of storage, but much of that is lost UPWARD
into the basement floor and therefore the house above it.)

If the storage could be warmed to 140°F, then the benefits would be
even better. The storage would then contain around 35 million Btus,
representing MOST of the house's heating load for each winter.
That means that, for every following winter, only a small portion
of the usual heating bills would be necessary! Forever!

If this heat storage capability is intended to be maximized, it is
easy to do. If the sub-basement was made 12 feet tall instead of
the 8 feet mentioned above, there would be one and one half times
as much heat storage capabilities. If the storage began in the
Autumn having been heated to 140°F, it's storage of 53 million Btu
should easily be able to entirely heat the whole house for the whole
winter, never having to turn on a furnace at all!

There is also the option of adding additional insulation around
the storage, to reduce even more the amount lost over a period
of months. Keep in mind that we estimate losing roughly 10 million
Btus over a three month period, and if the insulation was doubled,
that loss would only be around 5 million Btus during those three months.
For most climates, we do not encourage excessive insulation,
to keep expenses down.

To get your lofty thoughts back down to reality: A 2-inch thick layer
of blue foam insulation is rated at R-10. It would take TEN such layers
stacked up to get R-100 insulation! That's 20 inches thick of foam on all
walls and floor and ceiling! The chamber volume has been discussed
rather generically here in the calculations, but you can see that this
massive amount of insulation would materially reduce the available
volume of the storage material. More and more thicker insulation
can reduce the millions of Btus of heat loss, but also reduces the
total amount of heat stored in the smaller volume of material. For
each climate and application, there is generally a best thickness of
insulation, which can be determined with rather simple Calculus
solutions. And thicker insulation also would permit HOTTER storage
(due to slower heat loss) provided that you had some heat source
which could provide heat at higher than the Low-Grade heat (120°F
or 140°F or so) that we tend to find attractive! There are a zillion
options regarding this system! We (or a very talented Engineering
Firm) probably need to be involved in maximizing the design of a
system for any specific application. We know that people see this
as really obvious and apparently simple, and nearly everyone seems
to assume that they could build it without any help. Well, sort of!
It will certainly WORK no matter how poorly it was Engineered!
It's just that our attitude about such things is that IF you are going
to go to the trouble to do something like this, you might as well
do it right! Which means some calculation and Engineering toward
maximizing performance.

Summary

As mentioned, a taller storage chamber could be built, which would provide
even more heating and cooling storage. In certain climates, that might
be something worth considering. This discussion is making the
main point, that a rather conventional basement structure, a simple
basement, beneath the planned basement, could accomplish a
lot! For a rather moderate initial expense, a conventional air
conditioning system could very certainly be eliminated (saving a good
deal of installation money), ALL future years of air conditioning
electric bills would be essentially eliminated, and a great deal of
the cost of heating would also forever be eliminated! Best of all,
virtually all new construction could easily include this system, which is
entirely invisible once the house is built.

Also, please note that the re-sale value of a house that would
NEVER have any air conditioning expenses and would have possibly less than
half the winter heating expenses, would be VERY high. The additional
re-sale value of the house almost certainly would be greater than
the cost of installing this system! Also, do you realize how
quickly such a house would sell?

There ARE some Engineering considerations. All of the inner surfaces
of the (concrete) chamber would have to be painted / sealed to seal those
surfaces, such that moisture did not permeate through the concrete,
either inward or outward. Effective, crush-resistant, durable, thermal
insulation (we generally suggest an absolute minimum of R-30, but higher
R is always better, and R-60 or even R-100 might be appropriate for some
applications)
must be provided, so the storage does not lose too much of the
stored heat to the surrounding ground (such as what traditionally
had been called blue Styrofoam). Proper selection of the best storage
materials (for both economy and thermal characteristics) is very desirable.
Many people seem to instantly decide that either sand or rocks would be
the storage, but those materials actually have pretty terrible thermal
characteristics, and the storage would only have half or one-third
the storage capacity of our Design.
The system needs efficient ways to both get heat into and out of the
storage, for efficient performance. Otherwise, the house temperature could
vary from the desired wall thermostat value! When these considerations
are properly planned, an absolutely standard heating/cooling wall
thermostat can keep the entire house within one degree of the value
you set on that thermostat, for the ultimate in comfort, summer and
winter. It's all automatic, too! Alternately, different rooms could
have their own (standard) wall thermostats to control temperatures
separately, in a Zoned theme. Exactly like a standard central furnace
and central air conditioning system performs! No one living in the
house would even have to know that no conventional A/C was in operation
and no conventional furnace was being used!

As to specifics for a particular application, well, that's where we
might earn our keep. We would have liked to include those specifics in
this page, but there are quite a few variables that can affect
the performance of this system. The size and shape of a house, the
climate, and other variables can affect how this system should be
Engineered for optimum performance. Even occupant preferences and how
many kids would be opening doors all the time can be significant!

Actually, even without much planning at all, you can probably see how this
general idea is bound to be helpful, for both heating and cooling of
the house. So, really, you would not even need our help at all!
But, if you're going to do this, you might as well do a little planning
so that it will work really well. You should either do the math
yourself or have us do it (or provide the equations) or just over-estimate
how much storage material you will need, based on the heat capacity
of the material you choose. That is pretty easy to do, and the example
of the moderate sized house near Chicago is a good example. In a normal
Summer, only around 3.6 million Btus of cooling is likely to actually
be needed, but the calculations above show that over 11 million Btus
of cooling is available. This "over-design" is a good idea,
so that it would always provide excellent cooling, even for a record
hot summer. And, as an additional note on the actual air conditioning
usage, it is very rare that the compressor in a conventional central
A/C runs absolutely constantly for the six hours described. It generally
cycles on and off to keep the house temperature at what you set the
wall thermostat at. Therefore, the needed amount of cooling is
generally even less than the season total 3.6 million Btus stated.

The discussion above should have convinced you that almost any version
of this concept will be of benefit, but if you're going to do it,
you might as well get maximum benefit from it! The variables that
have the greatest effects on performance are three: (1) the insulation
R-factor used; (2) the type and condition of the storage medium itself;
and (3) the method of efficiently getting heat into and out of the
storage. In these areas, we have extensive understanding, and
we are confident that we can assure maximum performance of either
version of this system for any house and climate.

If you want our help, we have two possible fees that could be charged.

The first is a flat Cooling System - Technical Info Fee Arrangementfee of $250, for the
collection of plans, recommendations, equations, formulas, charts, drawings,
and a lot of additional guidance regarding designing the various parts of
the Free Air Conditioning system. This heat / cool storage system
is based on those same concepts and same equations, so that Technical
Packet can provide information such as the heat capacity of many different
storage materials which are commonly available, and the heat exchange
equations and numbers so the input / output arrangements could be designed.
If you happen to be or to know a thermodynamics engineer, he could
probably do all this for you and you wouldn't have to pay us anything!

The second
is a flat fee of $500 (for a single-family, fairly normal residential
house) which would involve US doing (minimal) design calculation work (of those
equations and formulas) necessary. For this, we would need you to supply us
with certain information, so we can take into consideration the size
of the house, the climate it is in, its estimated heating/cooling load,
the number of members of the family, etc., to determine the
engineering parameters, etc. of the components of this system. Many
variables are sometimes involved.

If more than an hour of our time might be expected to be needed
for a specific application, then our fee might be far higher.

If this is of interest to you, send us an e-mail (below) and we can send you
our mailing address.

This is one of two closely related "gifts" we are presenting
to the American people. This (storage) one is for new construction, (and
it is technically not entirely a gift, since you probably need to send us
one of the fees mentioned above), while the other one, the Free
Air Conditioning, is an approach for existing or new houses (and that
one really can be installed without ANY payment to us!). It is at:
Home Air Conditioning (1978, December 2000)

Larger Industrial Size

There are few realistic limits on the scale of this system.
An example was in progress during the Summer of 2008, when the
government of the country of India was intending to impress the
world with an entire City Airport Terminal (145,000 square feet
area, roughly the size of a hundred modern American houses),
being ENTIRELY SOLAR HEATED AND ALSO COOLED, forever,
without the otherwise $2 million annual heating bills and $1 million
annual cooling bills! The reasoning was to create the GREENest
large building on Earth! That installation was being designed to
use very large versions of the Sub-Basement storage (around 5 billion to
30 billion Btus of heat storage and 1 billion Btus of cooling storage)
(again, more than 100 times the seasonal energy needs of a normal-sized
American house). Some fields near the Terminal Complex were to
be used for very large applications of our Low-Tech Solar Heat
Collection system (maybe ten acres) to always keep the heat storage
replenished during long winters. (Ten acres of land is around 430,000 square
feet, each of which can receive around 300 Btu/hour of sunlight
energy near noon on a sunny day. That would be a maximum of around
130 million Btus received per hour. There are many sources of energy
loss in this low-tech approach, so 40 to 50 million Btus/hr of heat
collected in the warm air is realistic, or around 100 million Btus
during several hours of a reasonably sunny day. That is far more than the
entire daily heat loss of the entire Airport Terminal Complex, so
that single reasonably sunny day would provide enough heat [into storage]
for around a full week of the worst weather yet recorded for that
Airport.) All the participants agreed
that this unique system would give certainty of both heating
and cooling the entire Airport Terminal Complex, forever, with
NO need for fossil fuels ever again! It was expected to become
the world's largest building that was ENTIRELY heated by solar
heating (and also entirely cooled by environmentally compatible
methods.)

Unfortunately, there were a number of political complications in
India which arose in the Summer of 2008, and those plans got
shelved, at least for now. Apparently, there are some leaders
there who expect to soon use these methods to entirely heat
and cool, either that Airport or some other Airport in India,
but apparently such things must wait until politicians resolve
differences about other matters first!

The only reason that is mentioned here is that the basic concepts
of the Sub-Basement heat storage and the Low-Tech Solar Heat
Capture and Collection, are easily scalable for very large
applications. It seems likely that some large commercial
or industrial building, somewhere in the world, will install
this pair of systems, in order (1) to become GREEN; (2) to
save really massive amounts of heating and/or cooling utility bills;
and (3) to attract media attention for being an socially-responsible
company (or country).